Former Scottish Labour leader Jim Murphy told the same programme that on one occasion a member of the public had put a 12-pack of toilet roll on the Irn-Bru crates he was speaking on and told him: "Big man, this is for you, you've been talking shite all day, this is to clean up the mess."

Murphy, who was hit with an egg when he took his street campaign to Kirkcaldy in Fife, said there were occasions when the behaviour of some campaigners was "absolutely intimidating".

Better Together campaigner and then Labour MP Jim Murphy is hit with an egg in Dundee (Image: UGC)

He told the programme a group of about 100 people wearing Yes stickers had turned up when he spoke in Motherwell in what he described as a "completely orchestrated" incident.

The former MP recalled: "We set up our table with stickers and leaflets, they just kicked the table over.

"Pushing and jostling, just staying one side of the law. But for people there it was absolutely intimidating."

Blair McDougall, campaign director for the pro-UK, cross-party Better Together group, said Murphy's speaking tour of 100 towns across Scotland had to be suspended for a while "really for the safety of our staff".

TV historian Dan Snow, whose father-in-law was the super-rich landowner the 6th Duke of Westminster, told how he came in for online abuse when he became involved in the campaign.

His Let's Stay Together initiative featured celebrities including Sir Mick Jagger and Dame Judi Dench signing an open letter urging Scots to reject independence.

Jim Murphy went on a soap box tour of Scotland in 2014 as part of the pro British Better Together campaign (Image: PA)

He said: "I would love to sit here and say I found it bracing and it only strengthened my resolve to get involved in things I care about in the future but it was brutal."